Em. Hulzebos et al., PHYTOTOXICITY STUDIES WITH LACTUCA-SATIVA IN SOIL AND NUTRIENT SOLUTION, Environmental toxicology and chemistry, 12(6), 1993, pp. 1079-1094
The toxicity of 76 priority pollutants to lettuce (Lactuca sativa) was
determined in soil and in nutrient solution. In the first case a stat
ic and in the latter a semistatic exposure was established. Volatile a
nd easily degradable compounds had high EC50 values in soil (> 1,000 m
ug/g). In nutrient solution, however, several of these compounds were
rather toxic. Quantitative structure activity relationships (QSARs) re
lating EC50 values to log K(ow) could be described for the toxicity in
nutrient solution. Generally, the toxicity of the compounds increased
with increasing lipophilicity. Deviations were (partly) caused by rea
ctivity (N-containing compounds, double bonds in compounds), low lipop
hilicity (log K(ow) values < 1), and EC50 values close to solubility.
To relate toxicity in soil and nutrient solution, soil EC50 values wer
e recalculated to values in the soil pore water using calculated adsor
ption coefficients. Estimated pore-water EC50 values showed a good cor
relation with values determined in nutrient solution but were not equa
l to these values. The differences can be attributed to differences in
exposure (static vs. semistatic).